I need help on this?

0.15

Step-by-step explanation:

i assume you mean  3x^2 + 16y = 0

so y =  -3/16 x^2

The vertex is at the origin (0,0)  answer

x^2 = -16/3 y

compare with standard form x^2 = 4ay:-

the focus y coordinate of the  a =  -16/3  / 4

= -16/12 =  -4/3   so the focus is (0, -4/3) answer

and the directrix is y = 4/3  answer